(1) Field of the Invention
The present invention pertains to an apparatus and method for anchoring a subterranean well tool within a wellbore having casing.
(2) Description of the Prior Art
Subterranean well tools, such as packers, bridge plugs, tubing and other hangers, safety valves, fishing tools, and the like, typically are run into a well subsequent to casing being set and cemented into place. It is desirable to set such tools in the well along the casing against movements in at least one direction, such as against movements toward the top or bottom of the well, rotational movements, or any combination of such movements. Therefore, most such tools are provided with an anchoring assembly. The anchoring assembly is moved from a run-in position when the tool is being run in the well through the casing to the desired depth or location at which it is predetermined to be set and anchored in position. The anchoring means typically expands radially outwardly from the tool such that the anchor can grasp the outer wall of the casing, such as by teeth or otherwise, to prevent any such movements thereafter. Of course, it is extremely important that any such anchoring assembly included with any such subterranean well tool not be manipulatable between the run-in position to the set position, or there between, at any time that the well tool is being run into the well, or actuated in the well, prior to the time that it is determined to be anchored within the well, either for permanent setting of the well tool or temporary setting and withdrawal after a particular operation within the well has been effected. Any such premature actuation of the anchoring assembly could result in a failure of the tool to thereafter properly set at the desired location at the desired time, and, in dramatic instances, could result in the well tool, or other tool, becoming stuck in the well, necessitating a time consuming and otherwise expensive fishing operation to retrieve the well tool.
The present invention addresses the deficiencies in prior art devices, as generally described above.